Implantable devices for subchondral treatment of joint pain

ABSTRACT

Devices and associated methods are disclosed for treating bone, and particularly bone tissue at the joints. Disclosed are implantable devices that can be used either alone or in combination with this augmentation or hardening material for the repair of bone defects and which are particularly suited for use at the joints, and even more particularly, suited for use at the subchondral bone level.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional No. 61/324,931filed Apr. 16, 2010, and entitled “Implantable Devices for Treating BoneDefects,” U.S. Provisional No. 61/300,337 filed Feb. 1, 2010, andentitled “DEVICES AND INSTRUMENTS FOR BONE REPAIR AND METHODS OF USE,”U.S. Provisional No. 61/292,979 filed Jan. 7, 2010, and entitled“Instruments and Implants for Joint Repair and Methods of Use,” and U.S.Provisional No. 61/263,170 filed Nov. 20, 2009, and entitled “METHOD FORTREATING JOINT PAIN AND ASSOCIATED INSTRUMENTS,” which are hereinincorporated by reference in their entirety.

This application also relates to co-pending and co-owned U.S. patentapplication Ser. No. 12/950,355, filed Nov. 19, 2010 and entitled“SUBCHONDRAL TREATMENT OF JOINT PAIN,” U.S. patent application Ser. No.12/950,273, filed Nov. 19, 2010 and entitled “IMPLANTABLE DEVICES FORSUBCHONDRAL TREATMENT OF JOINT PAIN,” the content of which is hereinincorporated in its entirety by reference.

FIELD

The present invention relates to devices and instruments for thesurgical treatment of bone tissue, and more particularly to devices,instruments and associated methods for the surgical repair and treatmentof damaged or compromised bone tissue, especially at or near a joint.

BACKGROUND

Human joints, in particular the knee, hip and spine, are susceptible todegeneration from disease, trauma, and long-term repetitive use thateventually lead to pain. Knee pain, for example, is the impetus for awide majority of medical treatments and associated medical costs. Themost popular theory arising from the medical community is that knee painresults from bone-on-bone contact or inadequate cartilage cushioning.These conditions are believed to frequently result from the progressionof osteoarthritis, which is measured in terms of narrowing of the jointspace. Therefore, the severity of osteoarthritis is believed to be anindicator or precursor to joint pain. Most surgeons and medicalpractitioners thus base their treatments for pain relief on this theory.For example, the typical treatment is to administer pain medication, ormore drastically, to perform some type of joint resurfacing or jointreplacement surgery.

However, the severity of osteoarthritis, especially in the knee, hasbeen found to correlate poorly with the incidence and magnitude of kneepain. Because of this, surgeons and medical practitioners have struggledto deliver consistent, reliable pain relief to patients especially ifpreservation of the joint is desired.

Whether by external physical force, disease, or the natural agingprocess, structural damage to bone can cause injury, trauma,degeneration or erosion of otherwise healthy tissue. The resultantdamage can be characterized as a bone defect that can take the form of afissure, fracture, lesion, edema, tumor, or sclerotic hardening, forexample. Particularly in joints, the damage may not be limited to a bonedefect, and may also include cartilage loss (especially articularcartilage), tendon damage, and inflammation in the surrounding area.

Patients most often seek treatment because of pain and deterioration ofquality of life attributed to the osteoarthritis. The goal of surgicaland non-surgical treatments for osteoarthritis is to reduce or eliminatepain and restore joint function. Both non-surgical and surgicaltreatments are currently available for joint repair.

Non-surgical treatments include weight loss (for the overweightpatient), activity modification (low impact exercise), quadricepsstrengthening, patellar taping, analgesic and anti-inflammatorymedications, and with corticosteroid and/or viscosupplements. Typically,non-surgical treatments, usually involving pharmacological interventionsuch as the administration of non-steroidal anti-inflammatory drugs orinjection of hyaluronic acid-based products, are initially administeredto patients experiencing relatively less severe pain or jointcomplications. However, when non-surgical treatments prove ineffective,or for patients with severe pain or bone injury, surgical interventionis often necessary.

Surgical options include arthroscopic partial meniscectomy and loosebody removal. Most surgical treatments conventionally employ mechanicalfixation devices such as screws, plates, staples, rods, sutures, and thelike are commonly used to repair damaged bone. These fixation devicescan be implanted at, or around, the damaged region to stabilize orimmobilize the weakened area, in order to promote healing and providesupport. Injectable or fillable hardening materials such as bonecements, bone void fillers, or bone substitute materials are alsocommonly used to stabilize bone defects.

High tibial osteotomy (HTO) or total knee arthroplasty (TKA) is oftenrecommended for patients with severe pain associated withosteoarthritis, especially when other non-invasive options have failed.Both procedures have been shown to be effective in treating knee painassociated with osteoarthritis.

However, patients only elect HTO or TKA with reluctance. Both HTO andTKA are major surgical interventions and may be associated with severecomplications. HTO is a painful procedure that may require a longrecovery. TKA patients often also report the replaced knee lacks a“natural feel” and have functional limitations. Moreover, both HTO andTKA have limited durability. Accordingly, it would be desirable toprovide a medical procedure that addresses the pain associated withosteoarthritis and provides an alternative to a HTO or TKA procedure.

One of the difficulties of currently available devices and instrumentsis the lack of ability to control the injection of a hardening oraugmentation material into bone. Oftentimes, the injectable materialspreads out too much from its intended site, or is prone to backflow outof the bone or injection device. Further, where the bone defect occursat, or near, a joint region, the mechanical fixation devices need to beappropriately sized and configured to be easily inserted quickly andprecisely so as to avoid creating further trauma during its delivery.

Accordingly, it is desirable to provide devices and instruments that canallow precise, controlled injection of an augmentation or hardeningmaterial into bone. It is further desirable to provide implantabledevices that can be used either alone or in combination with thisaugmentation or hardening material for the repair of bone defects,particularly at the joints, and even more particularly at thesubchondral bone level.

SUMMARY

The present disclosure provides devices and instruments that can allowprecise, controlled injection of an augmentation or hardening materialinto bone. Also provided are implantable devices that can be used eitheralone or in combination with this augmentation or hardening material forthe repair of bone defects and which are particularly suited for use atthe joints, and even more particularly suited for use at the subchondralbone level.

In one exemplary embodiment, an implantable device for insertion intobone is provided. The device may include an elongate body extendingbetween a first, leading end and a second, trailing end, the second endincluding a tool-receiving portion for receiving a tool, the elongatebody including a central canal for receiving a flowable material, andhaving one or more channels in fluid communication with the centralcanal. The device may further include flutes on the elongate body. Theone or more channels may be located on one side of the device, and mayfurther reside within a recess along the elongate body.

In another exemplary embodiment, a system for treating a bone defect isprovided. The system may include an implantable device for insertioninto bone, the device comprising an elongate body extending between afirst, leading end and a second, trailing end, the second end includinga tool-receiving portion for receiving a tool, the first end having atapered tip, the elongate body including a central canal for receivingan injection tool, and having one or more channels in fluidcommunication with the central canal. The system may also include aninjection tool having a hollow shaft configured for insertion throughthe central canal of the implantable device, the shaft being capable ofreceiving a flowable material, and further including one or morechannels configured to align with one or more channels of theimplantable device to allow extrusion of the flowable material out ofthe injection tool and through the one or more channels of theimplantable device.

In yet another exemplary embodiment, a system for treating a bone defectis provided. The system may include a flowable material delivery devicefor insertion into bone, the device comprising a threaded elongate bodyextending between a first, leading end and a second, trailing end, thesecond end including a tool-receiving portion for receiving a tool, theelongate body including a central canal for receiving a flowablematerial, and having one or more channels in fluid communication withthe central canal. The system may further include an inserter toolhaving a handle extending into a shaft and terminating at adevice-attachment end, the device-attachment end being configured toattach to the second end of the delivery device. A protection sleeve mayalso be provided. The protection sleeve may include a tubular bodyhaving a handle at one end, and terminating at a bone-contacting surfaceat an opposite end, the tubular body including a threaded channelconfigured to threadedly receive the delivery device.

In still yet another exemplary embodiment, a method of treating a bonedefect is provided. The method includes the step of providing a firstimplantable device for insertion into bone, the device comprising anelongate body extending between a first, leading end and a second,trailing end, the second end including a tool-receiving portion forreceiving a tool, the elongate body including a central canal forreceiving a flowable material, and having one or more channels in fluidcommunication with the central canal. The method also includes providinga second implantable device for insertion into bone, the devicecomprising an elongate body extending between a first, leading end and asecond, trailing end, the second end including a tool-receiving portionfor receiving a tool, the elongate body including a central canal forreceiving a flowable material, and having one or more channels in fluidcommunication with the central canal. Next, the first and secondimplantable devices may be implanted such that one or more channels ofeach device is aligned. Flowable material may be injected into at leastone of the implantable devices.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosure. Additional features of thedisclosure will be set forth in part in the description which follows ormay be learned by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of thedisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1A is a perspective view of an exemplary embodiment of animplantable device of the present invention;

FIG. 1B is a perspective view of another exemplary embodiment of animplantable device of the present invention;

FIG. 1C is a perspective view of another exemplary embodiment of animplantable device of the present invention;

FIG. 2A illustrates perspective view of another exemplary embodiment ofan implantable device of the present invention;

FIG. 2B illustrates a perspective rear view of the implantable device ofFIG. 2A;

FIG. 2C illustrates a perspective front view of the implantable deviceof FIG. 2A;

FIG. 3A is a perspective view of the implantable device of FIG. 1 alongwith an injection instrument;

FIG. 3B is a perspective view of the implantable device of FIG. 1 alongwith another injection instrument;

FIG. 3C illustrates the implantable device and injection instrument ofFIG. 3A together;

FIG. 4A is a perspective view of another exemplary embodiment of animplantable device of the present invention;

FIG. 4B is a perspective rear view of the implantable device of FIG. 4A;

FIG. 4C shows a pair of implantable devices of FIG. 4A;

FIG. 4D shows a cross-sectional view of the implantable devices of FIG.4C along lines X-X;

FIG. 4E shows another perspective view of the implantable devices ofFIG. 4C;

FIG. 5A illustrates a perspective view of another exemplary embodimentof an implantable device of the present invention;

FIG. 5B illustrates a pair of implantable devices of FIG. 5A;

FIG. 5C shows a cross-sectional view of the implantable devices of FIG.5B along lines Y-Y;

FIG. 6A illustrates a perspective view of another exemplary embodimentof an implantable device of the present invention;

FIG. 6B illustrates another perspective view of the implantable deviceof FIG. 6A;

FIG. 7A illustrates an exemplary embodiment of an injection system ofthe present invention;

FIGS. 7B-7F illustrate a method of using the injection system of FIG.7A;

FIG. 8A is a perspective view of an exemplary embodiment of animplantable device of the present invention;

FIG. 8B is another perspective view of the implantable device of FIG.8A;

FIG. 9A is a perspective view of another exemplary embodiment of animplantable device of the present invention;

FIG. 9B is another perspective view of the implantable device of FIG.9A;

FIG. 10 is a partial cross-sectional view of the implantable device ofFIGS. 9A and 9B in situ;

FIGS. 11A-11C illustrate a method of using the implantable device ofFIG. 7;

FIG. 12A is a perspective view of yet another exemplary embodiment of animplantable device of the present invention;

FIG. 12B is another perspective view of the implantable device of FIG.12A;

FIG. 13A is a perspective view of yet another exemplary embodiment of animplantable device of the present invention;

FIG. 13B is another perspective view of the implantable device of FIG.12A;

FIG. 14 is a perspective view of still another exemplary embodiment ofan implantable device of the present invention;

FIGS. 15A and 15B illustrate a method of using the implantable device ofFIG. 14;

FIG. 16A is a perspective view of even still another exemplaryembodiment of an implantable device of the present invention;

FIG. 16B is another perspective view of the implantable device of FIG.16A;

FIG. 17 is a perspective view of another exemplary embodiment of animplantable device of the present invention;

FIG. 18A is a perspective view of still another exemplary embodiment ofan implantable device of the present invention;

FIG. 18B is an enlarged view of one end of the implantable device ofFIG. 18A; and

FIG. 19 is a perspective view of a second, trailing end of animplantable device of the present invention.

DESCRIPTION OF THE EMBODIMENTS

The present disclosure provides a methodology, devices and instrumentsfor diagnosing and treating joint pain to restore natural joint functionand preserving, as much as possible, the joint's articular and cartilagesurface. Treatments through the joint that violate the articular andcartilage surface often weaken the bone and have unpredictable results.Rather than focusing on treatment of pain through the joint, theembodiments diagnose and treat pain at its source in the subchondralregion of a bone of a joint to relieve the pain. Applicants havediscovered that pain associated with joints, especially osteoarthriticjoints, can be correlated to bone defects or changes at the subchondrallevel rather than, for example, the severity of osteoarthriticprogression or defects at the articular surface level. In particular,bone defects, such as bone marrow lesions, edema, fissures, fractures,hardened bone, etc. near the joint surface lead to a mechanicaldisadvantage and abnormal stress distribution in the periarticular bone,which may cause inflammation and generate pain. By altering the makeupof the periarticular bone (which may or may not be sclerotic) inrelation to the surrounding region, it is possible to change thestructural integrity of the affected bone and restore normal healingfunction, thus leading to a resolution of the inflammation surroundingthe defect.

Applicants have discovered that treatment of the bone by mechanical andbiological means to restore the normal physiologic stress distribution,and restore the healing balance of the bone tissue at the subchondrallevel, is a more effective way of treating pain than conventionaltechniques. That is, treatment can be effectively achieved bymechanically strengthening or stabilizing the defect, and biologicallyinitiating or stimulating a healing response to the defect. Accordingly,the present disclosure provides methods, devices, and systems for asubchondral procedure. This procedure and its associated devices,instruments, etc. are also marketed under the registered trademark nameof SUBCHONDROPLASTY™. The SUBCHONDROPLASTY™ procedure is a response to adesire for an alternative to patients facing partial or total kneereplacement.

In general, the SUBCHONDROPLASTY™ or SCP™ technique is intended to bothstrengthen the bone and stimulate the bone. In SCP™, bone fractures ornon-unions are stabilized, integrated or healed, which results inreduction of a bone defect, such as a bone marrow lesion or edema. Inaddition, SCP™ restores or alters the distribution of forces in a jointto thereby relieve pain. SCP™ can be performed arthroscopically orpercutaneously to treat pain by stabilizing chronic stress fracture,resolving any chronic bone marrow lesion or edema, and preserving, asmuch as possible, the articular surfaces of the joint. SUBCHONDROPLASTY™generally comprises evaluating a joint, for example, by taking an imageof the joint, detecting the presence of one or more subchondral defects,diagnosing which of these subchondral defects is the source of pain, anddetermining an extent of treatment for the subchondral defect. Thepresent technique is particularly suited for treating chronic defects orinjuries, where the patient's natural healing response has not resolvedthe defect. It should be noted, however, that the technique is equallyapplicable to treatment of defects in the subchondral region of bonewhere the defect is due to an acute injury or from other violations. Thepresent disclosure provides several exemplary treatment modalities forSCP™ for the different extents of treatment needed. Accordingly, amedical practitioner may elect to use the techniques and devicesdescribed herein to subchondrally treat any number of bone defects as hedeems appropriate.

In some embodiments, detection and identification of the relevant bonemarrow lesion or bone marrow edema (BML or BME) can be achieved byimaging, e.g., magnetic resonance imaging (MRI), X-ray, manualpalpation, chemical or biological assay, and the like. A T1-weighted MRIcan be used to detect sclerotic bone, for example. Another example isthat a T2-weighted MRI can be used to detect lesions, edemas, and cysts.X-ray imaging may be suitable for early-stage as well as end-stagearthritis. From the imaging, certain defects may be identified as thesource of pain. In general, defects that are associated with chronicinjury and chronic deficit of healing are differentiated from defectsthat result, e.g., from diminished bone density. SCP™ treatments areappropriate for a BML or BME that may be characterized as a bone defectthat is chronically unable to heal (or remodel) itself, which may causea non-union of the bone, stress or insufficiency fractures, andperceptible pain. Factors considered may include, among other things,the nature of the defect, size of the defect, location of the defect,etc. For example, bone defects at the edge near the articular surface orperiphery of a joint may be often considered eligible for treatment dueto edge-loading effects as well as the likelihood of bone hardening atthese locations. A bone defect caused by an acute injury would generallybe able to heal itself through the patient's own natural healingprocess. However, in such situations where the bone defect is due to anacute injury and either the defect does not heal on its own, or themedical practitioner decides that the present technique is appropriate,SCP™ treatments can be administered on acute stress fractures, BML orBME, or other subchondral defects, as previously mentioned.

According to the embodiments, the SCP™ treatment may continue aftersurgery. In particular, the patient may be monitored for a change inpain scores, or positive change in function. For example, patients arealso checked to see when they are able to perform full weight-bearingactivity and when they can return to normal activity. Of note, ifneeded, the SCP™ procedure can be completely reversed in the event thata patient requires or desires a joint replacement or other type ofprocedure. The SCP™ treatment may also be performed in conjunction withother procedures, such as cartilage resurfacing, regeneration orreplacement, if desired.

The present disclosure provides a number of treatment modalities, andassociated devices, instruments and related methods of use forperforming SUBCHONDROPLASTY™. These treatment modalities may be usedalone or in combination.

In one treatment modality, the subchondral bone in the region of thebone marrow lesion or defect can be strengthened by introduction of ahardening material, such as a bone substitute, at the site. The bonesubstitute may be an injectable calcium phosphate ensconced in anoptimized carrier material. In SCP™, the injected material may alsoserve as a bone stimulator that reinvigorates the desired acute bonehealing activity.

For example, polymethylmethacrylate (PMMA) or calcium phosphate (CaP)cement injections can be made at the defect site. PMMA injection mayincrease the mechanical strength of the bone, allowing it to withstandgreater mechanical stresses. CaP cement injection may also increase themechanical strength of the bone, while also stimulating the localizedregion for bone fracture repair. In one embodiment, the injection can bemade parallel to the joint surface. In another embodiment, the injectioncan be made at an angle to the joint surface. In yet another embodiment,the injection can be made below a bone marrow lesion.

In another treatment modality, the subchondral bone region can bestimulated to trigger or improve the body's natural healing process. Forexample, in one embodiment of this treatment modality, one or more smallholes may be drilled at the region of the defect to increase stimulation(e.g., blood flow, cellular turnover, etc.) and initiate a healingresponse leading to bone repair. In another embodiment, after holes aredrilled an osteogenic, osteoinductive, or osteoconductive agent may beintroduced to the site. Bone graft material, for example, may be used tofill the hole. This treatment modality may create a betterload-supporting environment leading to long term healing. Electrical orheat stimulation may also be employed to stimulate the healing processof a chronically injured bone. Chemical, biochemical and/or biologicalstimulation may also be employed in SCP™. For instance, stimulation ofbone tissue in SCP™ may be enhanced via the use of cytokines and othercell signaling agents to trigger osteogenesis, chondrogenesis, and/orangiogenesis to perhaps reverse progression of osteoarthritis.

In yet another treatment modality, an implantable device may beimplanted into the subchondral bone to provide mechanical support to thedamaged or affected bone region, such as where an insufficiency fractureor stress fracture has occurred. The implant may help create a betterload distribution in the subchondral region. In the knees, the implantmay support tibio-femoral compressive loads. In addition, the implantmay mechanically integrate sclerotic bone with the surrounding healthybone tissue. The implant may be placed in cancellous bone, throughsclerotic bone, or under sclerotic bone at the affected bone region. Theimplant may also be configured as a bi-cortical bone implant. In oneembodiment, one side of the implant can be anchored to the peripheralcortex to create a cantilever beam support (i.e., a portion of theimplant is inserted into bone but the second end stays outside or nearthe outer surface of the bone). The implant may be inserted using aguide wire. In one example, the implant may be inserted over a guidewire. In another example, the implant may be delivered through a guideinstrument. Exemplary guide instruments, navigation, and targetingsystems are also disclosed in co-pending and co-owned U.S. patentapplication Ser. No. 12/950,230, filed Nov. 19, 2010 and entitled“INSTRUMENTS FOR TARGETING A JOINT DEFECT,” U.S. patent application Ser.No. 12/950,154, filed Nov. 19, 2010 and entitled “INSTRUMENTS FORVARIABLE ANGLE APPROACH TO A JOINT,” U.S. patent application Ser. No.12/950,114, filed Nov. 19, 2010 and entitled “COORDINATE MAPPING SYSTEMFOR A JOINT TREATMENT,” U.S. patent application Ser. No. 12/950,061,filed Nov. 19, 2010 and entitled “NAVIGATION AND POSITIONING INSTRUMENTSFOR JOINT REPAIR,” the contents of which are herein incorporated intheir entirety by reference.

The implant may further be augmented with a PMMA or CaP cementinjection, other biologic agent, or an osteoconductive, osteoinductiveand/or osteogenic agent. The augmentation material may be introducedthrough the implant, around the implant, and/or apart from the implantbut at the affected bone region, such as into the lower region of a bonemarrow lesion or below the lesion. For example, the implant may act as aportal to inject the augmentation material into the subchondral boneregion.

While each of the above-mentioned treatment modalities may beadministered independent of one another, it is contemplated that anycombination of these modalities may be applied together and in any orderso desired, depending on the severity or stage of development of thebone defect(s). Accordingly, the present disclosure also providessuitable implantable fixation devices for the surgical treatment ofthese altered bone regions or bone defects, especially at thesubchondral level. Applicants have also discovered devices andinstruments that can be used in combination with cements or hardeningmaterials commonly used to repair damaged bone by their introductioninto or near the site of damage, either to create a binding agent,cellular scaffold or mechanical scaffold for immobilization,regeneration or remodeling of the bone tissue.

Turning now to the drawings, mechanical fixation devices particularlysuitable for implantation in certain areas of the bone, such as theperiarticular surface or the subchondral bone area (usually within therange of about 2-15 mm from the bone surface) are shown. Referring nowto FIG. 1A, an exemplary embodiment of an implantable device of thepresent disclosure is shown. Implant 10 can include an elongate body 16extending between a proximal, leading end 12 and a distal, trailing end14. The distal end 14 may include a tool-receiving portion (not shown)for receiving a tool, such as an insertion tool (not shown in FIG. 1A).The proximal end 12 of the implant 10 can include a tapered nose or tip18 to facilitate ease of insertion to the target site.

In addition, a surface feature may be present on the elongate body 16for enhanced bone tissue engagement with the target site. In theembodiment shown, the surface feature may comprise a fin 20. One or morefins 20 can be provided in the present embodiment. The fins 20 of FIG.1A may have a uniform height across their length, or the fins 20 mayhave varying heights across their length to create a curved, wavy, orirregular pattern. For example, the fins 20 may be S-shaped, V orW-shaped to create a jagged spine-like profile along the length of theelongate body 16. It is contemplated that the surface feature may alsoinclude structural elements such as teeth, barbs, bumps, spikes, orother surface enhancements.

While the elongate body 16 is shown as being substantially cylindrical,it is understood that the elongate body 16 may be shaped so as to havevarying diameters along its length. For instance, the elongate body 16may have a figure “8” shape, a bowling pin shape, a U-shape, a crescentor C-shape, an I-beam shape, a rectangular or square shape, a starshape, or corkscrew shape, etc. so long as it is suitable for insertioninto bone tissue and has enough structural integrity to perform itsintended function of bridging a fracture or fissure, supporting boneregrowth or remodeling, and/or binding the bone tissue together toprevent further breakdown or degeneration.

If desired, the surface feature may include a biological agent. Thebiological agent may be included in a coating on the implant 10.Alternatively, the biological agent may be embedded inside the implant10. Suitable biological agents may include, for example, osteogenic,osteoconductive and/or osteoinductive agents. In addition, a bioactiveagent such as platelet rich plasma, for example, may also be employed.Furthermore, a bioactive surface may be created on the implant 10 bytreating the implant 10 with, for example, acid etching, grit blasting,plasma spraying, or other suitable surface treatments.

The implant 10 may be formed of any suitable biocompatible material,including metal or polymer materials. Suitable metals may include, butare not limited to, stainless steel, titanium, titanium alloys, andcobalt chrome, as examples. Porous metals may also be appropriate. Theimplant 10 may also be ABS injection molded plastic,polyetheretherketone (PEEK), polyethylene (PE), or ultra high molecularweight polyethylene (UHMWPE). If desired, the implant 10 may bebioabsorbable or bioresorbable. In some embodiments, the implant 10 maybe formed of allograft or cadaver bone, including cortical,cortico-cancellous, bi-cortical, tri-cortical, or sesamoid bonematerial. In other embodiments, the implant 10 may be formed of aradiolucent material. In addition, radiopaque markers may be employedwith the implant 10 for imaging possibilities.

FIG. 1B illustrates another exemplary embodiment of an implantabledevice of the present disclosure, where the fenestrated implant 30 hasthe same elements as implant 10 (with like numerals designating the sameelements) and further includes side channels 32 extending through theelongate body 16. One or more pores or side channels 32 can be provided.The fenestrated implant 30 may include a central channel (not shown) forreceiving a fluidic material, such as a bone void filler or bone cement.The central channel may be in fluid communication with the side channels32 to allow excess material injected into the implant 30 to seep or oozeout and around the elongate body. Additionally, the side channels 32 mayallow some tissue growth into the implant 30 through these same channels32. If desired, additional perforations may be provided to allow betterfluid transfer through the implant 30, and further may allow vessels togrow through the perforations.

FIG. 1C illustrates another exemplary embodiment of a device of thepresent disclosure. In similar fashion to the embodiments shown in FIGS.1A and 1B, implant 30 can include an elongate body 16 extending betweena first, leading end 12 and a second, trailing end 14. The second end 14may include tabs 26 to for receiving an insertion tool (not shown). Thefirst end 12 of the implant 10 can include a tapered nose or tip 18 tofacilitate ease of insertion to the target site. For example, as shown,the tip 18 may have a relatively sharper tapered tip or bullet-like nosein order to facilitate insertion of the implant 30.

The elongate body 16 may further include recesses or flutes 24 extendingalong the longitudinal axis of the implant 30 and around thecircumference of the elongate body 16. The implant 30 may be providedwith a central opening or canal 28 extending longitudinal along themajor axis, as shown, or it may be cannulated as is common in the art.Although shown with a closed tip 18, it is envisioned that the tip 18may be open if desired, so as to allow the implant 30 to slide entirelyover a guide wire for insertion. Further, the implant 30 may befenestrated, with pores or channels 32 also provided on the flutes 20.The pore or channels 32 may be in fluid communication with the centralopening 28 of the implant 30.

As previously mentioned, the implant 30 may further be augmented with aPMMA or CaP cement injection, other biologic agent, or anosteoconductive, osteoinductive and/or osteogenic agent like a bonegraft material. The augmentation material may be introduced through theimplant, around the implant, and/or apart from the implant but at theaffected bone region, such as into the lower region of a bone marrowlesion. For example, the implant may act as a portal to inject theaugmentation material into the bone tissue.

The present embodiment provides structural features to accommodate thesescenarios. It is contemplated that the second end 14 of the implant 30may be configured to allow a quick release connection with a tool, suchas for example a threaded connection. As shown, the tabs 26 on thesecond end 14 provide a simple and quick mechanism for attachment to aninsertion tool or even an injection system. The tool could be, forexample, an insertion tool, an injection needle, or a catheter. In oneembodiment, the tabs 26 can create a bayonet-type connection whereby theimplant 30 can be inserted and twisted to lock into the tool or system.Alternatively, the implant 30 may be provided with a Luer lock-typemechanism for attachment to an injection system. The central opening 28would enable the augmentation material to be introduced through theimplant 30, while the channels 32 would allow the material to be ejectedaround the implant 30. The flutes 24 around the elongate body 16 createvoids or open space around the implant 30 to accommodate theaugmentation material. The pores or channels 32 can also provide accessfor bone ingrowth and vasculature permeation. The pores or channels 32may be provided in any variety of sizes; however, it is understood thatadjustment of the pore size would allow the user to control the flow ofan injectable material through the implant 30. By making the pores 32smaller, resistance to flow is increased and alternatively by making thepores 32 larger, resistance to flow is reduced. It is thereforecontemplated that the implant 30 may be provided with suitably sizedpores 32 for use with the intended injectable material desired. Forinstance, the pores or channels 32 may have a larger dimension than thecentral opening 28, creating a path of least resistance for injectedmaterial through the channels 32 and thereby reducing backflow out ofthe central opening 28.

As further shown, it is possible to provide an implant 30 with thechannels 32 in only region of the elongate body 16. FIG. 1C illustratesan implant 30 whereby the channels (or pores) 32 are located along oneside of the implant 30 to allow the user to control the directionalityand flow of the injectable material to be used. In one example, theimplant 30 may be inserted so that the channels 32 face towards a bonedefect. When an injectable material is introduced into the implant 30and allowed to extrude from the channels 32, it is possible to inject insuch a way to enable the material to bounce off the surface of the bonedefect and subsequently surround the implant 30. Although not shown, itis contemplated that a plug or cap may be provided with implant 30 inorder to seal off the central opening 28 and thereby prevent anyaugmentation material contained within to leak out.

In similar fashion as implant 10, the implant 30 may be formed of anysuitable biocompatible material, including metal or polymer materials.Suitable metals may include, but are not limited to, stainless steel,titanium, titanium alloys, and cobalt chrome, as examples. Porous metalsmay also be appropriate. The implant 30 may also be ABS injection moldedplastic, polyetheretherketone (PEEK), polyethylene (PE), or ultra highmolecular weight polyethylene (UHMWPE). If desired, the implant 30 maybe bioabsorbable or bioresorbable. In some embodiments, the implant 30may be formed of allograft or cadaver bone, including cortical,cortico-cancellous, bi-cortical, tri-cortical, or sesamoid bonematerial. In other embodiments, the implant 30 may be formed partiallyor wholly from a radiolucent material. For example, the implant may beformed from a material blended with a radiopaque material, such asbarium sulfate. In addition, radiopaque markers may be employed with theimplant 30 for imaging possibilities.

While the elongate body 16 is shown as being substantially cylindrical,it is understood that the implant 30 may be shaped so as to have varyingdiameters along its length. For instance, the implant 30 may have anoverall threaded configuration, a figure “8” shape, a bowling pin shape,a U-shape, a crescent or C-shape, an I-beam shape, a rectangular orsquare shape, a star shape, or corkscrew shape, etc. so long as it issuitable for insertion into bone tissue and has enough structuralintegrity to perform its intended function of bridging a fracture orfissure, supporting bone regrowth or remodeling, and/or binding the bonetissue together to prevent further breakdown or degeneration.

The implants 10, 30 of the present disclosure may be used to repair bonedefects in a joint region such as the knee, shoulder, ankle, hip orother joint of the patient's body. The implants may be useful, forexample, in repairing an insufficiency fracture of a bone at a joint.The implants may serve as a fusion device, enabling rigid fixation atthe defect site. For instance, the implants may serve as a useful facetfusion device. Alternatively, the implants may be configured tofacilitate the patient's natural healing process without fusion at thedefect site.

If desired, the implants 10, 30 may also include a biological agent. Thebiological agent may be included in a coating on the implants 10, 30.Alternatively, the biological agent may be embedded inside the implants10, 30. Suitable biological agents may include, for example, osteogenic,osteoconductive and/or osteoinductive agents. In addition, a bioactiveagent such as platelet rich plasma (PRP), bone marrow aspirate (BMA),bone morphogenic protein (BMP), demineralized bone matrix (DBM), stemcells, or allograft material, for example, may also be employed.Furthermore, a bioactive surface may be created on the implants 10, 30by treating the implant 10, 30 with, for example, acid etching, gritblasting, plasma spraying, bioactive glass coating, photo-chemicaletching, or other suitable surface treatments for creating a roughenedsurface. While the implants have been described as being used with aninjectable material, it is understood, however, that the implants shownhere, as well as the other implants and devices described herein, may beused alone without any injectable material.

FIGS. 2A-2C illustrate an implantable device 40 similar in many ways toimplants 10 or 30, but with an additional surface feature for enhancedbone tissue engagement. Implant 40 may include a first, leading end 42and a second, trailing end 44 extending between which is an elongatebody 46. Like implant 10, implant 40 can further include a tapered nose48, flutes 50 extending longitudinally along its body 46, a centralcanal 60, and one or more pores 54 in communication with the centralcanal 60. In addition, the implant 40 may include a collar or cap 56 atthe second, trailing end 44. The cap 56 may include fins 58 extendingaround its diameter as shown, along with a slot 64 for receiving a tool,such as for example an insertion tool or an injection instrument (notshown).

The fins 58 enable the implant 40 to be inserted in a combinationslip-fit, press-fit manner. The implant 40 may have primary stabilitywith the press-fit connection of the fins 58 to the bone tissue, whilethe remaining surface of the implant 40 may be further stabilized aftera cement is injected through the implant 40 and allowed to harden, aspreviously described. In addition, the cap 56 may also serve to preventcement from escaping out of the bone tissue and away from the implant 40during injection.

The fins 58 may have a uniform height across their length, or the fins58 may have varying heights across their length to create a curved,wavy, or irregular pattern. For example, the fins 58 may be S-shaped, Vor W-shaped to create a jagged spine-like profile. Further, instead offins 58, it is contemplated that the surface feature on the cap 56 mayalso include structural elements such as threads, teeth, barbs, bumps,spikes, or other surface enhancements. These surface enhancements mayserve as anti-migration features after implantation. In addition, ahydroxyapatite coating may also be applied to enhance incorporation intothe surrounding bone tissue.

FIGS. 3A-3C illustrate a system 100 for controlling the manner ofinjecting a bone cement or hardening material, or a bone augmentationmaterial, into a bone defect. Turning to FIG. 3A, the system 100 mayinclude an implantable device such as implant 30 (or implant 10) and aninjection tool 80 configured for use with the implant 30. Injection tool80 may have a first, leading end 82, a second, trailing end 84, a shaft86 extending in between, and one or more pores 88 on the shaft 86. Theinjection tool 80 may be sized and configured to slide into the implant30, as shown in FIG. 3C. When the pores 88 of the injection tool 80 donot match up with the pores 32 of the implant 30, no material can beextruded. But when extrusion is desired, the injection tool 80 may beadjusted or rotated such that its pores 88 align with the pores 32 onthe implant 30 and thereby enable the injected material to be extrudedout of the implant 30.

As shown in FIG. 3B, the injection tools 80, 80′ may vary in the numberof pores 88 provided as well as the orientation of the pores 88. In thepresent example shown, an injection tool 80′ is similar in most respectsto injection tool 80, except that less pores 88′ are provided, and thepores 88′ are located only at a select region of the tool 80′. To enablea user to selectively control the directionality of flow of theinjectable material, the injection tool 80′ may be utilized with implant30. Material would only extrude where the pores 32 of the implant andthe pores 88′ of the injection tool 80′ align.

FIGS. 4A-4E illustrate yet another exemplary embodiment of animplantable device 110 of the present invention that can be used incombination with an injectable material, if desired. Implant 110 mayinclude a first, leading end 112 and a second, trailing end 114extending between which is an elongate body 116. Implant 110 can furtherinclude a recessed portion 120, and one or more pores 124 residingwithin the recessed portion 120. The pores 124 may be in communicationwith a central canal 130 extending through the longitudinal axis of theimplant 110. In addition, the implant 110 may include a flanged collar134 at the second, trailing end 114. The flanged collar 134 may includea tool-engaging slot, such as a hexagonal slot 136.

In use, the recessed portion 120 of the implant 110, which includes thepores 124, enables the user to control the directionality of the flow ofinjectable material being extruded. The recessed portion 120 also servesto contain the area where the material resides. Additionally, theflanged collar 134 may serve to block extruded material from escapingout of the implantation site.

FIGS. 4C-4E show one manner of using one or more implants 110 of thepresent invention. In one example, a pair of implants 110 may be used incombination with one another in a manner that allows communicationbetween the implants 110. In some situations, it may be desirable toimplant a pair of devices in parallel into the area of the bone defectto be treated. The devices may be arranged as shown in FIGS. 4C-4E, withthe pores 124 facing one another. This configuration would enable theuser with the ability to irrigate the site using one implant 110, andcollect out of the other implant 110. For example, it is contemplatedthat one implant 110 may be closed to avoid leakage, while the otherimplant 110 opened to irrigate, in order to allow the user the abilityto manipulate the directionality of materials being extruded from theopened implant 110. It would be possible, for instance, to inject amaterial into one implant, and allow the material to extrude out of theimplant and into the pores 124 of the other implant if so desired. It isalso possible to utilize multiple implants in this manner to stage, orspace apart, the timing or introduction of material into the bonedefect. For example, one material may be introduced earlier into animplant, while another material may be introduced at a later time intothe other implant. The materials may be the same, or may be different.Of course, such a process is possible where the pores 124 of theimplants 110 are aligned with one another, as shown in cross-section inFIG. 4D.

This same concept of multiple implant usage of implants in communicationwith one another may be employed with the threaded device 140 of FIGS.5A-5C. Device 140 may include a first, leading end 142 and a second,trailing end 144 extending between which is an elongate body or shaft146. A portion of the shaft 146 may include threads 148, as shown.Device 140 can further include a recessed portion 150, and one or morepores 154 residing within the recessed portion 150. The pores 154 may bein communication with a central canal 160 extending through thelongitudinal axis of the device 140. In addition, the device 140 mayinclude a cap 162 at its second, trailing end 144. The cap 162 mayextend into a collar 164 extending partially down the shaft 146. Asshown in FIG. 5C, the cap 162 may also include a tool-engaging slot 166for receiving an insertion tool or an injection tool, for example.

By providing a device 140 with threads 148, it is possible that thedevice 140 be implanted and left inside the bone, or it can be removedfrom the bone by screwing the device 140 back out of the bone. In eitherscenario, the cap 162 as well as the collar 164 serve as shoulders orramps to prevent any extruded material through the device 140 frombacking out.

FIGS. 6A and 6B illustrate a device 170 of the present disclosure thatis configured to allow cortical bone purchase or anchorage. The device170 may include a first, leading end 172 and a second, trailing end 174extending between which is an elongate shaft (or body) 176. A portion ofthe shaft 176 may include threads 178, as shown, while a central canal190 extends through the shaft 176. Pores 184 are provided at the regionwith threads 178, and are in fluid communication with the central canal190. The device 170 further includes a flange 180 with a surface featureon its underside for improved bone purchase. In the embodiment shown,the surface feature may include spikes (or teeth) 182, for example. Acap 192 is also provided with a tool-engaging slot 196 for receiving aninsertion tool or an injection tool, for example.

Since the pores 184 are isolated at the threaded portion of the device170, this particular embodiment allows the user better control of wherethe injectable material is extruded. Further, the spiked flange 180allows the device 170 additional anchorage and stability, and isparticularly useful where the device 170 is secured to the outer bonesurface. Accordingly, it is possible to provide devices where a portionis inside bone and a portion remains outside the bone. In the presentexample, the cap 192 of the device 170 may sit proud outside of the bonesurface, although it is contemplated that the device 170 could be easilyconfigured so that the cap 192 has an overall low profile outside of thebone.

FIGS. 7A-7F represent a system 200 and method of using the system 200 toinject a bone cement or other hardening material, or a bone augmentationmaterial such as a biologic agent, into a bone defect. The system 200comprises a threaded device 210 similar to the threaded devices 140, 170already described above. However, threaded device 210 may includethreads 218 along its entire length, and act as a drill bit. Thethreaded device 210 may include a first, leading end 212 and a second,trailing end 214 extending between which is an elongate shaft (or body)216 having threads 218 extending along its length. Pores 224 may beprovided in between the threads 218, as shown, though it is contemplatedthat the pores 224 may also be provided on the threads 218, if desired.

System 200 further includes an insertion tool 240 configured for usewith the threaded device 210. The tool 240 may include a first,device-attachment end 242 that may provide a quick release connectionwith the device 210. For example, the device-attachment end 242 may be athreaded end. The insertion tool 240 also includes an elongate shaft (orbody) 246 extending from the device-attachment end 242 into a second,opposed end 244. The second end 244 may be configured with a contouredhandle 248. The contoured handle 248 may include an opening 250 with aninjection port 252 that extends through the length of the tool 240 andis in communication with a central canal (not shown) running down thelength of the threaded device 210.

Also provided with system 200 is a protection sleeve 270 configured foruse with the threaded device 210 and the insertion tool 240. Theprotection sleeve 270 may include a rounded or smooth bone-contactingend 272 and a device insertion end 274 at an opposite end. A tubularbody 276 may extend in between the first and second ends 272, 274. Thetubular body 276 may include a threaded channel 278 that matches thefemale threads 218 of the threaded device 210. A handle 280 may beprovided on the tubular body 276.

In use, the threaded device 210 may be attached to the insertion tool240, as shown in FIG. 7A. Then, the protection sleeve 270 may be placedwith the first, bone-contacting end 272 against the bone 2 to betreated, as shown in FIG. 7B. The bone-contacting end 272 may be eitherround and/or smooth, or it may be roughened for better bone contact, ifdesired. While holding the protection sleeve 270 firmly against the bone2 using handle 280, the threaded device 210 may be threaded into theprotection sleeve 270 and into the bone 2, which may or may not alreadyhave a bone cavity pre-drilled to receive the threaded device 210. Oncethe threaded device 210 is inside the bone 2 (see FIG. 7F), an injectiontool (not shown) may be attached to the injection port 252 at the handle248 of the insertion tool 240. The desired injectable material may thenbe injected through the insertion tool 240, into the threaded device210, and allowed to extrude out of one or more pores 224 of the threadeddevice 210 into the bone 2.

In one method of using the system 200 of the present disclosure, one ormore threaded devices 210 may be employed in the bone 2 to be treated. Aquantity of injectable material, such as a bone cement, can be injectedand allowed to extrude into the bone 2. After some period of timesufficient to allow the cement to harden, the threaded device(s) 210 maybe retracted by unscrewing it/them out of the protection sleeve 270.Material may be injected again, allowed to harden, and the threadeddevice 210 retracted. These steps may be repeated until sufficientcement has been extruded and hardened, whereupon the threaded device(s)210 may be removed from the bone 2 entirely in stages, as shown in FIGS.7C-7E. The protection sleeve 270 prevents cement from backing out, orextruding out of the bone 2 during the entire process, as the user holdsthe sleeve 270 firmly against the bone 2 throughout the procedure.

System 200 provides the user with a plurality of working channels forinjecting a cement or other injectable material into a bone 2 to betreated. These working channels may be coaxial, as shown, and enable theuser to inject some or all of the material at once, or in a stagedfashion to control the injection process. In an example where an openended device is employed, cement may be injected at the open end onlyand allowed to harden so as to close off the open end. Subsequently,additional cement or other material may be injected through the rest ofthe device so that the material extrudes out through provided pores orchannels and not through the open end. In addition, system 200 may beused with any of the threaded devices disclosed herein, allowing thedevices to serve as a drill bit as well as an injection tool.

FIGS. 8A and 8B illustrate yet another exemplary embodiment of animplantable device of the present disclosure. Implant 320 can include anelongate body or shaft 326 extending between a first, leading end 322and a second, trailing end 324. Elongate body 326 may be provided withexternal threads 334 extending along its length. The first end 322 ofthe implant 320 can include a tapered nose or tip 328 to facilitate easeof insertion to the target site. If so desired, the tip 328 may also berounded. The implant 320 may be configured to be self-tapping,self-drilling, or the implant 320 may be configured for insertion afterthe creation of a pre-drilled hole in the bone being treated.

The second end 324 may include a head region 330 having a tool-engagingopening 332 for receiving an insertion tool (not shown). Thistool-engaging opening 332 may also extend into a central channel 340that stretches down the length of the implant 320 a predetermineddistance, such as for example, half-way down its length, three-quartersdown its length, etc. As shown, the elongate body 326 may have a cutawayportion 336 that creates a flattened, depressed surface on the elongatebody 26. One or more side ports 342 may be provided on the cutawayportion 336, with each side port 342 being in communication with thecentral channel 340. The side ports 342 enable the user to introduce aflowable material, such as a bone cement or augmentation material aspreviously described, into the central channel 340 and allow thematerial to extrude out of the side ports 342 and away from the elongatebody 326.

Although shown with a plurality of side ports 342, each being similar insize, it is understood that the dimensions of the side port 342 mayvary. For example, it is contemplated that the side ports 342 may haveincremental sizes along the length of the elongate body 326. Also, theside ports 342 may have a predetermined geometric pattern, such as forexample, a staggered arrangement, instead of being coaxial.

FIGS. 9A and 9B illustrate another exemplary embodiment of animplantable device of the present disclosure. Implant 420 is similar toimplant 320 previously described. Like implant 320, implant 420 may alsoinclude an elongate body 426 extending between a first, leading end 422and a second, trailing end 424. Elongate body 426 may be provided withexternal threads 434 extending along its length. The first end 422 ofthe implant 420 can include a tapered nose or tip 428 to facilitate easeof insertion to the target site, while the second end 424 may include ahead region 430 having a tool-engaging opening 432 for receiving aninsertion tool (not shown). This tool-engaging opening 432 may alsoextend into a central channel 440 that stretches down the length of theimplant 420 a desired distance.

As FIG. 9B shows, the elongate body 426 may have a pair of cutawayportions 436, creating flattened, depressed surfaces on opposed lateralsides of the elongate body 426. Each cutaway portion 436 may include oneor more side ports 442, with each side port 442 being in communicationwith the central channel 440 to enable the user to introduce a flowablematerial, such as a bone cement or augmentation material as previouslydescribed, into the central channel 440 and allow the material toextrude out of the side ports 442 and away from the elongate body 426.

FIGS. 10 and 11A-11C illustrate one exemplary method of use in which theimplant 420 may be used to treat a bone defect in a bone 2 of a joint.As shown in partial cross-section in FIGS. 10 and 11A-11C, the bonedefect may be a bone marrow lesion 6 at the subchondral level below thearticular surface 4 of a tibia of a knee joint. The implant 420 may bepositioned in the tibia bone 2 below the bone marrow lesion 6 such thatthe external threads 434 on the elongate body 426 faces toward thelesion 6, as further shown in partial cross-section in FIG. 11B. Thisarrangement allows greater surface area contact between the lesion 6 andthe implant 420, thereby providing more mechanical strength andstructural integrity to the area to be treated, than if the implant 420was rotated 90 degrees, for instance, where one of the cutaway portions436 faced the bone marrow lesion 6.

Once the implant 420 is properly positioned relative to the defect orlesion 6, a flowable material 70 may be introduced into the centralchannel 440 of the implant 420 and extruded out through the side ports442. The flowable material 70, which may be a hardening or augmentationmaterial such as a bone cement (e.g., PMMA or CaP cement) or a bioactiveagent (e.g, an osteoconductive, osteoinductive and/or osteogenic agentlike a bone graft material), may be allowed to extrude away from theelongate body 426 and into the tissue of bone 2 surrounding the bonemarrow lesion 6, as shown in partial cross-section in FIG. 11C.Accordingly, the implant 420 facilitates the dispersal of hardening oraugmentation material in the area adjacent the bone marrow lesion 8 tofurther increase mechanical stability and/or enhance biological activityin order to treat or repair the structural makeup of the bone 2 in thatregion.

FIGS. 12A and 12B illustrate yet another exemplary embodiment of animplantable device of the present disclosure. Implant 520 is similar toimplant 320 previously described. Like implant 320, implant 520 may alsoinclude an elongate body 526 extending between a first, leading end 522and a second, trailing end 524. The first end 522 of the implant 520 caninclude a tapered nose or tip 528 to facilitate ease of insertion to thetarget site, while the second end 524 may include a head region 530having a tool-engaging opening 532 for receiving an insertion tool (notshown). This tool-engaging opening 532 may also extend into a centralchannel that stretches down the length of the implant 520 a desireddistance.

Like implant 420, implant 520 may have a pair of cutaway portions 536,creating flattened, depressed surfaces on opposed lateral sides of theelongate body 526. Each cutaway portion 536 may include one or more sideports 542, with each side port 542 being in communication with thecentral channel to enable the user to introduce a flowable material,such as a bone cement or augmentation material as previously described,into the central channel and allow the material to extrude out of theside ports 542 and away from the elongate body 526.

However, unlike implant 320, implant 520 may be provided without anyexternal threads, such that the implant 520 may be configured forpress-fit engagement with bone tissue. The head region 530 of theimplant 520 may have threads 544 to secure the implant 520 in place onceproperly positioned relative to the bone defect. These threads 544 mayallow the head region to be secured to the cortical wall of the bone 2(or tibia, in the case of a knee joint) near the lesion 6, which isstronger bone. Further, the threads 544 may act to help seal the headregion 530 of the implant 520 into the bone opening to prevent extrusionof the flowable material or back-out of the implant 520. It iscontemplated that any of the implants described and shown herein may beprovided with a head region having such external threads for the reasonsjust mentioned.

FIGS. 13A and 13B shown still another exemplary embodiment of animplantable device of the present disclosure. Implant 620 is similar toimplant 320 previously described. Like implant 320, implant 620 mayinclude an elongate body 626 extending between a first, leading end 622and a second, trailing end 624. Elongate body 626 may be provided withexternal threads 634 extending along its length. The first end 622 ofthe implant 620 can include a tapered nose or tip 628 to facilitate easeof insertion to the target site, while the second end 624 may include ahead region 630 having a tool-engaging opening 632 for receiving aninsertion tool (not shown). This tool-engaging opening 632 may alsoextend into a central channel 640 that stretches down the length of theimplant 620 a desired distance.

Like implants 420 and 520, implant 620 may have a pair of cutawayportions 636, creating flattened, depressed surfaces on opposed lateralsides of the elongate body 626. A primary slot 646 may extend betweenthe flattened surfaces of the cutaway portions 636, as shown. Theprimary slot 646 may be configured to be open and communicate with thecentral channel 640 to allow extrusion of a flowable material from thecentral channel 640 into the slot 646 and outside the elongate body 626.One or more additional, or secondary slots 646′, may also be provided.These secondary slots 646′ extend between the cutaway portions 636similar to primary slot 646. However, the secondary slots 646′ are notin communication with the central channel 640.

In one exemplary method of treating a bone defect using implant 620, theimplant 620 may be positioned below the bone defect such that theexternal threads 634 on the elongate body 626 faces toward the defect,similar to the arrangement shown in FIG. 10 and FIG. 11B. As describedearlier, this arrangement allows the greatest surface area contactbetween the defect and the implant 620, thereby providing bettermechanical strength and structural integrity to the area to be treated.After proper placement of the implant 620 relative to the defect, aflowable material may be introduced into the central channel 640 of theimplant 620 and allowed to extrude into the primary slot 646. Furtherextrusion may be allowed such that the material flows out of the primaryslot 646 and into one or more secondary slots 646′ provided with theimplant 620. It is contemplated that the open slots 646, 646′ allow foreasier transmission of cement and/or bone material from one side of theimplant 620 to the other near the area of the lesion 6. The open slots646, 646′ could also allow for bony ingrowth into the implant 620 tofurther secure the implant to the bone

FIG. 14 illustrates yet another exemplary embodiment of an implantabledevice of the present disclosure. Implant 720 shares similarcharacteristics to implant 320 previously described. Implant 720 mayinclude an elongate body 726 extending between a first, leading end 722and a second, trailing end 724. Elongate body 726 may be provided withexternal threads 734 extending along its length, and may be cannulatedfor use with a guide wire 90. As shown, the central channel 740 may bedimensioned to allow a K-wire 90, guide wire, or other equivalentinsertion pin to pass through.

Unlike implant 20, however, the first end 722 of the implant 720terminates at flat end surface 748. The second end 724 may include ahead region 730 having an insertion tool-engaging opening similar tothose previously described and shown. Also, as shown, the elongate body726 is substantially cylindrical, with no cutaway portions thereabout.

FIGS. 15A and 15B illustrate one exemplary method of treating a bonedefect using implant 720. In the illustrated example, the bone 2 may bea femur of a knee joint, and the bone defect may be a bone marrow lesion6 in the subchondral level below the articular surface 4 of a femur. Apre-drilled hole may be created to facilitate insertion of the implant720, as shown in FIG. 15A. As the implant 720 is advanced towards thebone marrow lesion 6, tissue of bone 2 surrounding the defect becomescompacted against the lesion 6, as shown in FIG. 15B. It has beendiscovered that the bone tissue 2 surrounding a bone marrow lesion 6tends to be relative soft (usually, edema is present) compared withnormal, healthy bone tissue. Accordingly, one method of treating thelesion 6 is to compact the soft bone tissue 2 at the site of the lesion6.

Although not shown, if desired, a flowable material such as the bonecements or augmentation materials previously described could also beintroduced through the implant 720 to provide additional reinforcementor mechanical stability, and/or biological activity in the region.

FIGS. 16A and 16B illustrate even still another exemplary embodiment ofan implantable device of the present disclosure. Implant 820 is similarto implant 320 previously described. Like implant 320, implant 820 mayalso include an elongate body 826 extending between a first, leading end822 and a second, trailing end 824. Elongate body 826 may be providedwith external threads 834 extending along its length. The first end 822of the implant 820 can include a tapered nose or tip 828 to facilitateease of insertion to the target site, while the second end 824 mayinclude a head region 830 having an insertion tool-engaging opening (notshown). This tool-engaging opening may also extend into a centralchannel 840 that stretches down the length of the implant 820 a desireddistance.

As FIG. 16B shows, the elongate body 826 may have a pair of segmentalcutaway portions 850 that have a general appearance of approximately aquarter cross-sectional area of the cylindrical elongate body 826. Thesegmental cutaway portions 850 appear on opposed lateral sides of theelongate body 826. Each segmental cutaway portion 850 may intersect thecentral channel 840 to create a slot 852 within the segmental cutawayportion 850. The open slot 852, being in communication with the centralchannel 840, allows the user to introduce a flowable material, such as abone cement or augmentation material as previously described, into thecentral channel 840 and allow the material to extrude out of the slots842 away from the elongate body 826.

FIG. 17 illustrates yet still another exemplary embodiment of animplantable device of the present disclosure. Implant 920 shares thesame structural elements and characteristics of implant 820 previouslydescribed. Implant 920 can include an elongate body 926 extendingbetween a first, leading end 922 and a second, trailing end 924.Elongate body 926 may be provided with external threads 934 extendingalong its length. The first end 922 of the implant 920 can include atapered nose or tip 928 to facilitate ease of insertion to the targetsite, while the second end 924 may include a head region 930 having aninsertion tool-engaging opening (not shown). This tool-engaging openingmay also extend into a central channel 940 that stretches down thelength of the implant 920 a desired distance.

Like implant 820, the elongate body 926 may have segmental cutawayportions 950 that have a general appearance of approximately a quartercross-sectional area of the cylindrical elongate body 926. However, inthis embodiment, there may be a plurality of smaller segmental cutawayportions 950 on either of the lateral sides of the implant 920, insteadof a single, longer portion 950 on each lateral side as with implant920. In fact, each lateral side of the elongate body 926 may include twoor more segmental cutaway portions 950 as desired.

Again, each segmental cutaway portion 950 may intersect the centralchannel 940 to create a slot 952 within the cutaway portion 950. Theopen slot 952, being in communication with the central channel 940,allows the user to introduce a flowable material, such as a bone cementor augmentation material as previously described, into the centralchannel 940 and allow the material to extrude out of the slots 952 awayfrom the elongate body 926.

In use, it is contemplated that implants 820, 920 would be positionedbelow the bone defect such that the external threads 834, 934 on theelongate bodies 826, 926 face towards the defect. As described earlier,this arrangement allows the greatest surface area contact between thedefect and the implants 820, 920, thereby providing better mechanicalstrength and structural integrity to the area to be treated. Afterproper placement of the implants 820, 920 relative to the defect, aflowable material may be introduced into the central channel 840, 940 ofthe implant 820, 920 and allowed to extrude out of the slots 852, 952and away from the elongate bodies 826, 926.

FIGS. 18A and 18B illustrate even still another exemplary embodiment ofan implantable device of the present disclosure. The implant 1020 mayinclude a first, leading end 1022, a second, trailing end 1024, and anelongate body 1026 extending between the ends 1022, 1024. The first,leading end 1022 may terminate at a flat end surface 1048, while thesecond, trailing end 1024 may terminate at a head region 1030. The headregion 1030 may include a tool-engaging opening 1032 for receiving aninsertion tool (not shown). The tool-engaging opening 1032 may extendinto a central channel 1040 that may extend into the elongate body 1026.External threads 1034 may be provided on the elongate body 1026, asshown. In addition, a side port 1054 may be provided in communicationwith the central channel 1040 near the first, leading end 1022.

In one exemplary method of using implant 1020, the implant 1020 may beinserted adjacent a bone defect. Then, a flowable material may beintroduced through the central channel 1040 and extruded out the sideport 1054 such that the flowable material is extruded near the first,leading end 1022 of the implant 1020. The flowable material may be abone cement or augmentation material, as previously described. It iscontemplated that the implant 1020 may be utilized in the same manner asdescribed for implant 720 to compact soft bone tissue of bone 2surrounding the lesion 6, whereupon the flowable material introduced atthe first, leading end 1022 can be extruded in the area adjacent thecompacted bone.

FIG. 19 illustrates yet another exemplary embodiment of an implantabledevice of the present disclosure. Implant 1120 is similar to implant 320previously described. Like implant 320, implant 1120 may include anelongate body 1126 extending between a first, leading end 1122 and asecond, trailing end 1124. Elongate body 1126 may be provided withexternal threads 1134 extending along its length. The second end 1124may include a head region 1130 having a tool-engaging opening 1132 forreceiving an insertion tool (not shown). This tool-engaging opening 1132may also extend into a central channel 1140 that stretches down thelength of the implant 1120 a desired distance.

In addition, the opening 1132 may have a geometry that would allow theuser to determine the directionality of the implant 1120. For example,as shown, the tool-engaging opening 1132 may have a shape of anisosceles triangle. Other shapes are contemplated, and thecharacteristics of this shaped tool-engaging opening 1132 may beemployed in any of the embodiments of the present disclosure, in orderto allow directional control over the positioning of the implants intobone.

It is contemplated that the various implants described herein may beformed of any suitable biocompatible material, including metal orpolymer materials. Suitable metals may include, but are not limited to,stainless steel, titanium, titanium alloys, and cobalt chrome, asexamples. Porous metals may also be appropriate. The implant may also beABS injection molded plastic, polyetheretherketone (PEEK), polyethylene(PE), or ultra high molecular weight polyethylene (UHMWPE). If desired,the implant may be bioabsorbable or bioresorbable. In some embodiments,the implant may be formed of allograft or cadaver bone, includingcortical, cortico-cancellous, bi-cortical, tri-cortical, or sesamoidbone material. In other embodiments, the implant may be formed partiallyor wholly from a radiolucent material. For example, the implant may beformed from a material blended with a radiopaque material, such asbarium sulfate. In addition, radiopaque markers may be employed with theimplant for imaging possibilities.

While the elongate bodies of the implants are shown as beingsubstantially cylindrical, it is understood that the implants may beshaped so as to have varying diameters along its length. For instance,the implants may have an overall figure “8” shape, a bowling pin shape,etc. so long as it is suitable for insertion into bone tissue and hasenough structural integrity to perform its intended function of bridginga fracture or fissure, supporting bone regrowth or remodeling, and/orbinding the bone tissue together to prevent further breakdown ordegeneration.

The implants of the present disclosure may be used to repair bonedefects in a joint region such as the knee, shoulder, ankle, hip orother joint of the patient's body. The implants may be useful, forexample, in repairing an insufficiency fracture of a bone at a joint.The implants may serve as a fusion device, enabling rigid fixation atthe defect site. Alternatively, the implants may be configured tofacilitate the patient's natural healing process without fusion at thedefect site.

If desired, the implants may also include a biological agent. Thebiological agent may be included in a coating on the implant.Alternatively, the biological agent may be embedded inside the implant.Suitable biological agents may include, for example, osteogenic,osteoconductive and/or osteoinductive agents. In addition, a bioactiveagent such as platelet rich plasma (PRP), bone marrow aspirate (BMA),bone morphogenic protein (BMP), demineralized bone matrix (DBM), stemcells, or allograft material, for example, may also be employed.Furthermore, a bioactive surface may be created on the implant bytreating the implant with, for example, acid etching, grit blasting,plasma spraying, bioactive glass coating, photo-chemical etching, orother suitable surface treatments for creating a roughened surface.

As noted, while the implants have been described as being used with aninjectable or flowable material, it is understood, however, that theseimplants shown and described herein may be used alone without anyinjectable or flowable material if so desired. In some instances wherethere is bone deformity, and a bone defect must be resected, it isdesirable to provide a suitable implantable device that can be placedinto the void left by the resected bone. The implantable device may beinserted in an open procedure, or it may be inserted in a minimallyinvasive procedure if the bone tissue is soft enough to accommodate theimplantable device in this fashion.

Other embodiments will be apparent to those skilled in the art fromconsideration of the specification and practice of the embodimentdisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope and spirit of theembodiment being indicated by the following claims.

What is claimed is:
 1. An implantable device for treating a subchondralbone defect of a bone of a joint, comprising: an elongate body extendingbetween a first, leading end and a second, trailing end, the second endincluding a tool-receiving portion for receiving a tool, the elongatebody including a central canal for receiving a flowable material, andhaving one or more channels in fluid communication with the centralcanal for dispersing the flowable material, the channels being locatedalong one side of the elongate body; the elongate body furthercomprising a depressed, cutaway portion for containing the area wherematerial extrudes, the one or more channels residing within thedepressed, cutaway portion; wherein the implantable device is configuredto serve as both a mechanical support to stabilize the subchondral bonedefect, and as a portal to disperse the flowable material in adirectionally controlled manner to the subchondral bone defect fortreatment of the defect; and further wherein the implantable device isconfigured to be implanted into a subchondral level of the bone whilestill preserving the articular surface of the bone.
 2. The device ofclaim 1, wherein the tool-receiving portion comprises a tab.
 3. Thedevice of claim 1, wherein the second end includes fins.
 4. The deviceof claim 3, wherein the device is configured to be slip-fitted andpress-fitted into the bone.
 5. The device of claim 1, wherein the secondend includes a cap.
 6. The device of claim 1, further comprisingexternal threads along a length of the elongate body.
 7. The device ofclaim 6, wherein the depressed, cutaway portion resides within theexternal threads.
 8. The device of claim 1, further including a flangehaving a surface feature for anchorage to an outer surface of the bone.9. The device of claim 8, wherein the surface feature comprises spikes.10. The device of claim 1, wherein the tool is an insertion tool, aninjection needle, or a catheter.
 11. The device of claim 1, wherein thefirst end is tapered.
 12. The device of claim 1, wherein the flowablematerial is a bone cement, bone graft material, biologic agent,osteoconductive agent, osteoinductive agent, or osteogenic agent.
 13. Asystem for treating a subchondral bone defect of a bone of a joint,comprising: an implantable device for insertion into bone, the devicecomprising an elongate body extending between a first, leading end and asecond, trailing end, the second end including a tool-receiving portionfor receiving a tool, the first end having a tapered tip, the elongatebody including a central canal for receiving an injection tool, andhaving one or more channels in fluid communication with the centralcanal for dispersing the flowable material, the channels being locatedalong one side of the elongate body; the elongate body furthercomprising a depressed, cutaway portion for containing the area wherematerial extrudes, the one or more channels residing within thedepressed, cutaway portion; wherein the implantable device is configuredto serve as both a mechanical support to stabilize the subchondral bonedefect, and as a portal to disperse the flowable material in adirectionally controlled manner to the subchondral bone defect fortreatment of the defect; and further wherein the implantable device isconfigured to be implanted into a subchondral level of the bone whilestill preserving the articular surface of the bone; and an injectiontool having a hollow shaft configured for insertion through the centralcanal of the implantable device, the shaft being capable of receivingthe flowable material, and further including one or more channelsconfigured to align with one or more channels of the implantable deviceto allow extrusion of the flowable material out of the injection tooland through the one or more channels of the implantable device.
 14. Thesystem of claim 13, wherein the injection tool includes the same amountof channels as the implantable device.
 15. The system of claim 13,wherein the injection tool includes less channels than the implantabledevice.
 16. The system of claim 13, wherein the channels of theinjection tool are configured in the same spatial arrangement as thechannels of the implantable device.
 17. The system of claim 13, whereinthe channels of the injection tool are configured in a different spatialarrangement than the channels of the implantable device.
 18. A systemfor treating a subchondral bone defect of a bone of a joint, comprising:a flowable material delivery device for insertion into bone, the devicecomprising a threaded elongate body extending between a first, leadingend and a second, trailing end, the second end including atool-receiving portion for receiving a tool, the elongate body includinga central canal for receiving a flowable material, and having one ormore channels in fluid communication with the central canal fordispersing the flowable material, the channels being located along oneside of the elongate body; the elongate body further comprising adepressed, cutaway portion for containing the area where materialextrudes, the one or more channels residing within the depressed,cutaway portion; wherein the implantable device is configured to serveas both a mechanical support to stabilize the subchondral bone defect,and as a portal to disperse the flowable material in a directionallycontrolled manner to the subchondral bone defect for treatment of thedefect; and further wherein the implantable device is configured to beimplanted into a subchondral level of the bone while still preservingthe articular surface of the bone; and an inserter tool having a handleextending into a shaft and terminating at a device-attachment end, thedevice-attachment end being configured to attach to the second end ofthe delivery device.
 19. The system of claim 18, further including aprotection sleeve including a tubular body having a handle at one end,and terminating at a bone-contacting surface at an opposite end, thetubular body including a threaded channel configured to threadedlyreceive the delivery device.
 20. The system of claim 18, wherein thebone-contacting surface of the protection sleeve is smooth.
 21. Thesystem of claim 18, wherein the bone-contacting surface of theprotection sleeve is roughened to enhance bone attachment.